JPH09207247A - Paper sheet for molding and molding of container using this paper sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a web composed mainly of pulp for molding a container with a presentable appearance and free from fissures and cracks by setting the height of a corrugation located in an area which is widely stretched to be partially larger than that of a corrugation in any other area, when a container is molded. SOLUTION: In a paper sheet for molding a container which is composed mainly of pulp and continuously connected paper sheets, a corrugation is formed vertically at least, to the web feed direction, and the height of a corrugation located in an area which is widely stretched is set partially larger than that of a corrugation in any other area. This web 1 is caused to pass between clamping rolls 3 driven by a servo motor 2 and then is discharged to the outside of a device passing through a corrugating press 4, an intermediate clamp 6, a molding die 7 and a rear clamp 9 installed alongside the molding die 7 for the container. The corrugating press 4 is equipped with a corrugation molding die 5 with a corrugated pattern intended for the purpose, insetted to the top and the bottom die plate.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a continuous paper sheet for molding a container composed of a paper sheet containing pulp as a main raw material, and a method for molding a container using the paper sheet, and more particularly to a packaging container, a food container, or the like. The present invention relates to a forming paper sheet used for forming the paper container of 1. and a method for forming a container using the paper sheet.

[0002]

2. Description of the Related Art Conventionally, as a container that can be easily disposed of after use, a container formed of a sheet containing pulp as a main raw material (hereinafter sometimes simply referred to as a paper sheet) is used instead of a container made of synthetic resin. It is known to do.
However, since the paper sheet lacks plasticity like a synthetic resin, it is difficult to apply the molding means adopted when molding the synthetic resin sheet to the paper sheet. Therefore, there is a method of forming a container after corrugating a continuous paper sheet. For example, JP-A-5-309766 and JP-A-7-214705 disclose a method in which a container is formed after corrugation is performed by a pair of wrinkled rolls having a corrugated surface. Further, Japanese Patent Application Laid-Open No. 49-13265 discloses a method of forming a two-dimensional wrinkle and then thermoforming as the corrugating process.

In the method of corrugating with a pair of wrinkled rolls, the corrugated shape can be easily obtained with a constant pitch and a constant height, but a container usually consists of a bottom and side walls. , The method of stretching differs depending on the part when molding. Therefore, if the corrugated shape described above is provided in conformity with the most stretched portion, there is a problem in that the corrugated portion is too high in the portion that is not stretched so much that wrinkles occur and a container with a good appearance cannot be molded. In addition, if the corrugated shape is provided according to the part that is not stretched so much,
Cracks, cracks, etc. occur in the most stretched part,
This causes a problem that a container having a good appearance cannot be molded.
JP-A-49-13265 for processing two-dimensional wrinkles
As a concrete example of this processing, the same type of gear is stacked on the same shaft with a spacer in between, and adjacent teeth are shifted by half a pitch and fixed, and a sheet is supplied between them as a pair. It is described as being processed. In such a method, the corrugating process is intermittent, and cracks, cracks and the like are likely to occur in the intermittent portion of the molded container, and a container having a good appearance cannot be molded.

[0004]

Therefore, the present inventor has completed the present invention as a result of various studies in order to solve these problems, and the present invention does not cause cracks, cracks, etc., and has an external appearance. An object of the present invention is to provide a continuous paper sheet for forming a container mainly made of pulp for forming a good container and a method for forming a container using the paper sheet.

[0005]

DISCLOSURE OF THE INVENTION The gist of the present invention is a container-forming paper sheet comprising a continuous paper sheet containing pulp as a main raw material, and having a corrugate at least in a direction perpendicular to the flow direction, and the corrugate. Is a corrugating process which is a corrugating process in which the corrugated height of a portion that is greatly stretched when molding a container is partially higher than the corrugated height of other regions. In a method for forming a container from a formed paper sheet having, a continuous paper sheet containing pulp as a main raw material is supplied to a corrugating machine, and at least in a direction perpendicular to the flow direction, a corrugate at a portion greatly stretched when forming the container. Corrugation is performed so that the height is partially higher than the corrugated height of other parts, and then the container A method of molding a container from the molding sheet of paper having a corrugated to a feature that is press-molded.

That is, according to the present invention, when a paper container is formed by using a continuous paper sheet, when the container is formed, the portion that is strongly stretched in the flow direction of the paper sheet and the portion that is strongly stretched toward the left side are strongly stretched. Since there is a part that is not stretched and strong stress is applied to the part that is strongly stretched, cracks in the part that is greatly stretched by molding the corrugated height of this part partially higher than the corrugated height of other parts. , It prevents cracks, etc., and the corrugated height at other parts is made lower, so it is difficult for wrinkles to enter,
Further, it is possible to mold a container having a good appearance in which corrugated marks are not noticeable.

Hereinafter, the present invention will be described in detail. The paper sheet used in the present invention is a continuous sheet containing pulp as a main raw material, and is 5 with respect to 100 of pulp such as wood.
An olefin resin can be mixed and used in a range not exceeding 0% by weight. From the standpoint of moldability, it is preferable to use 5 to 30% by weight of the olefin resin to be mixed. Examples of the olefin resin include polyethylene and polypropylene, and these can be used alone or in combination. Further, the paper sheet used in the present invention can be used by laminating the above-mentioned olefin resin or polyester resin film on at least one surface. Examples of the polyester resin include polyethylene terephthalate, polyethylene isophthalate, polybutylene terephthalate, polyethylene terephthalate-isophthalate copolymer, and the like, in addition to typical polyethylene terephthalate.

The corrugating process performed in the present invention is formed on at least a direction perpendicular to the flow direction, preferably a direction perpendicular to the flow direction and a direction perpendicular to the flow direction, most preferably a side surface of the container in accordance with the shape of the container to be molded. The corrugate of all parts is processed higher than the other parts.
Here, the direction perpendicular to the flow direction means, for example, as shown in FIG. 3, the flow direction of the paper sheet is from left to right in the figure, a
When it is a direction, it means a direction perpendicular to the direction, that is, the b direction. The corrugated pattern is formed by molding the corrugated height of a portion that is largely stretched when molding the container to be partially higher than the corrugated height of other portions, and the state is shown in the side view of FIG. Then, the corrugated height of the c portion corresponding to the side surface of the container is made larger than the corrugated height of the d portion corresponding to the bottom surface of the container. Further, this corrugating process is preferably provided in the same direction as the flow direction of the paper sheet according to the shape of the container to be molded as shown in FIGS. 4 and 5, and the most preferable embodiment is the shape of the container to be molded. Corrugated pattern is provided on the part corresponding to the side of the container. This corrugated pattern is the part corresponding to the side surface of the container, the height of the corrugated part formed in the c part is the other part,
Process to a height higher than the height of the corrugated part d. It is preferable to use a press machine as the corrugating means. This is because the corrugated pattern that matches the shape of the container to be molded as described above can be easily processed. The corrugated shape is not particularly limited and may be appropriately set according to the shape and depth of the container to be molded, but normally, the corrugated height and pitch are 1 to 10 mm, and the height is 1 to 10.
It is preferable to provide the corrugated pattern in a range of 8 mm, and the corrugated pattern to be formed to have a high height is formed in the range of 3 to 8 mm in height.
The corrugated pattern is formed at a lower height in other portions.

The corrugated paper sheet is then formed into a container. It is the most preferable mode of corrugating that the corrugated part of the side surface of the container is processed higher than the other parts. At the time of molding the container, it is preferable to use matchmaking using a press die. This is because the corrugated pattern that matches the shape of the container to be molded can be easily processed.

Next, this method will be described with reference to the drawings.
FIG. 1 is an explanatory view showing an example of an apparatus for carrying out the container molding method according to the present invention. In FIG. 1, an original 1 made of a paper sheet is moved by a feed servomotor 2 and a ball screw. The raw fabric 1 passes between the clamp rolls 3 driven by the servomotors 2 and passes the corrugated press machine 4, the intermediate clamp 6, the molding die 7, and the rear clamp 9 provided beside the molding die 7 of the container. Be sent to the outside of the device. The corrugated press machine 4 is equipped with a corrugated die 5 having a desired corrugated pattern on the upper and lower plates,
It is a press machine that moves up and down by a press cylinder.
In the press 8 having the container molding die 7, the molding die is attached to the heater. A match mold is preferable as the molding die 7 for the container. In such a series of devices, a molded product is sent out of the device by a ball screw and at the same time, a raw material is sent into the device. At the same time as the rear clamp 9 is closed, the intermediate clamp 6 existing between the corrugated part and the molding part of the container is closed, and the original fabric 1 is clamped and fixed. At the same time, the clamp roll 3 is rotated to supply the original fabric into the corrugated part. At this time, 10 to 20% excess length of the raw fabric sent to the container molding unit is supplied into the corrugated molding unit, and the raw fabric is sagged in the corrugated molding unit. Then, the corrugated molding device and the container molding device are simultaneously operated. After a certain period of time, the press bases of the corrugate molding device and the container molding device are opened to return to the initial state, and the molded product is sent out of the device by the ball screw and at the same time, the raw material is supplied into the device. In this apparatus, however, a ball screw and a servomotor are used to continuously transfer a fixed amount of material. FIG. 2 shows another apparatus for performing the molding method according to the present invention. In this apparatus, a corrugated metal mold and a container molding die are arranged in one press machine, and the front and rear of this press machine are the same as those in FIG. Then, a spring is provided between the corrugated metal mold of the press machine and the container molding mold so as to fix the original fabric to be molded.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Next, the present invention will be described more specifically with reference to Examples. Example 1 A paper sheet containing pulp as a main raw material, mixed with 10% by weight of polyethylene and having a thickness of 0.6 mm and a basis weight of 350 g / m 2.
^Two consecutive sheets were used. A roll of this sheet was used. This continuous paper sheet is shown in Figure 1.
A container is molded using the apparatus shown in. First, a corrugated press was used to perform corrugation as shown in FIG. The corrugated height of the corrugated height of the portion where the side wall provided in the direction perpendicular to the flow direction of the container, which is greatly extended when the container is formed, has a pitch of 3 mm and the height is 3 mm. For the other portions, the corrugated height was 3 mm in pitch and 1.5 mm in height. Further, this corrugated press working was performed with the mold temperature set at 70 ° C. In the next step, a press mold was used and a match mold was used to mold at a mold temperature of 140 ° C. and a pressing time of 10 seconds. Molded product has a width of 110 mm and a length of 180 m
A container having a volume of m and a depth of 22 mm and an internal capacity of about 280 cc was molded. The obtained container had a good appearance with no cracks or cracks on the side walls or side wall corners, and no wrinkles on the bottom.

Example 2 A paper sheet containing pulp as a main raw material was prepared by mixing 5% by weight of polyethylene with a thickness of 0.8 mm and a basis weight of 450 g / m ^2.
Of continuous sheets of. A roll of this sheet was used. In the next step, this continuous sheet was concentrically corrugated as shown in FIG. 5 using a corrugating press. The corrugated height of the portion forming the side wall of the container was 5 mm in pitch and its height was 3 mm, and the corrugated height in other portions was 5 mm in pitch and its height was 1.5 mm. Further, this corrugated press working was performed with the mold temperature set at 70 ° C. In the next step, a press mold was used and a match mold was used to mold at a mold temperature of 140 ° C. and a pressing time of 10 seconds. As the shape of the molded product, a container having a diameter of 140 mm and a depth of 22 mm and an internal capacity of about 230 cc was molded. The obtained container had a good appearance with no cracks or cracks on the side walls or side wall corners, and no wrinkles on the bottom.

[0013]

EFFECTS OF THE INVENTION Since a continuous sheet is used for forming a paper container, it is strongly stretched partially in the direction of flow of the sheet during molding of the container, and is strong in this portion. Since stress is applied, by partially molding the corrugated height of this part higher than the corrugated height of other parts, cracks in the part that is greatly stretched,
Since cracks and the like are prevented and the corrugated height at other portions is formed to be lower, it is possible to mold a container having a good appearance in which wrinkles are hard to enter and corrugated marks are not noticeable.

[Brief description of drawings]

FIG. 1 is an explanatory view of an apparatus for carrying out a molding method of the present invention.

FIG. 2 is an explanatory view of another apparatus for carrying out the molding method of the present invention.

FIG. 3 is a plan view and a side view of a molded paper sheet according to the present invention.

FIG. 4 is a plan view and a side view of a corrugated pattern formed in Example 1.

FIG. 5 is a plan view and a side view of a corrugated pattern formed in Example 2.

[Explanation of symbols]

1 Raw Fabric 2 Servo Motor 3 Clamp Roll 4 Corrugated Press Machine 5 Corrugated Mold 6 Intermediate Clamp 7 Container Molding Die 8 Container Molding Press 9 Rear Clamp

Claims (2)

[Claims] 1. A container-forming paper sheet comprising a continuous paper sheet containing pulp as a main raw material, and having corrugates at least in a direction perpendicular to a flow direction, and the corrugates are largely stretched when molding the container. A molded paper sheet, which is corrugated so that the height of the corrugated part is partially higher than that of other parts. 2. A method for forming a container from a formed paper sheet having corrugating, wherein a continuous paper sheet containing pulp as a main raw material is supplied to a corrugating machine to form the container at least in a direction perpendicular to the flow direction. Corrugation processing is performed so that the corrugated height of the part that is greatly stretched at that time is partially higher than the corrugated height of the other parts, and then press-molded into a container. A method of molding a container.